Torque source

ABSTRACT

Various apparatus and methods are disclosed for providing torque.

BACKGROUND

Sheets of media are sometimes moved or fed through a device, such as aprinter. In some instances, the sheets may travel through the device ata rate faster than expected which may result in mishandling of thesheet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of one embodiment of a media feedsystem according to one example embodiment.

FIG. 2 is a schematic illustration of a media interaction systemincluding another embodiment of the media feed system of FIG. 1according to one example embodiment.

FIG. 3 is a side elevation view schematically illustrating anotherembodiment of a media interaction system according to one exampleembodiment.

FIG. 4 is a fragmentary top perspective view of another embodiment ofthe media feed system of FIG. 1 with portions schematically shownaccording to one example embodiment.

FIG. 5 is an exploded perspective view of a portion of the media feedsystem of FIG. 4 according to one example embodiment.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 is a schematic illustration of one example of a media feed system10. Media feed system 10 is configured to feed, drive or otherwise movea sheet 12 of media to a destination within a device such as a printer,scanner and the like. System 10 generally includes media drive member14, torque source 16 and compliant coupler 30. Media drive member 14constitutes a member configured to be rolled against a surface of medium12 so as to drive medium 12 to the subsequent destination. In theparticular example illustrated, media drive member 14 constitutes aroller configured to be rotatably driven about axis 32. In otherembodiments, media drive member 14 may constitute other devicesconfigured to frictionally engage a sheet 12 to move or drive the sheet12. For example, in another embodiment, media drive member 14 mayconstitute a belt driven about multiple axes and rolled against medium12.

Torque source 16 constitutes a device configured to provide rotationaltorque for rotatably driving media drive member 14. In one embodiment,torque source 16 may comprise a motor. In other embodiments, othertorque source 16 may constitute other sources of torque.

Compliant coupler 30 constitutes one or more members configured totransmit torque from torque source 16 to media drive member 14 torotatably drive member 14. At the same time, compliant coupler 30 isconfigured to reduce or cease the transmission of torque from torquesource 16 to media drive member 18 in response to a predeterminedcounter force or counter torque exerted upon compliant coupler 30through media drive member 14. In one embodiment, compliant coupler 30is configured to reduce or cease the transmission of torque to mediadrive member 14 in response to sheet 12 encountering an obstructionwhile being moved by media drive member 14 such that media drive member14 will discontinue driving sheet 12. As a result, compliant coupler 30prevents or minimizes a likelihood of mishandling of media 12 such as amedia jam within a device.

In operation, torque source 16 supplies torque to media drive member 14through compliant coupler 30 so as to drive media drive member 14 and soas to move sheet 12 towards a destination. If sheet 12 reaches thedestination before anticipated by the subsequent destination or beforethe subsequent destination is ready to receive sheet 12, sheet 12 mayencounter an obstruction such as a belt, roller or other device that mayprevent or inhibit further movement of sheet 12. If torque from torquesource 16 were continued to be supplied to media drive member 14 todrive sheet 12, sheet 12 may become crumpled, jammed or otherwise bemishandled. However, compliant coupler 30 prevents continuedtransmission of torque to media drive member 14 in such a circumstanceby ceasing further transmission of torque to drive member 14 whiletorque source 16 continues to supply torque. Thus, mishandling of mediais prevented or minimized.

In the particular embodiment illustrated in FIG. 1, compliant coupler 30constitutes a member configured to absorb or store torque from torquesource 16 in response to a predetermined level of counter torque beingapplied to compliant coupler 30 as a result of sheet 12 encountering anobstruction at the subsequent destination. In one particular embodiment,compliance coupler 30 constitutes a torsion spring which rotates totransmit torque between torque source 16 and media drive member 14. Uponmedia sheet 12 encountering an obstruction, a counter force or countertorque is applied to the torsion spring through media drive member 14.As a result, the torsion spring constituting compliant coupler 30 twiststo store the torque which is continued to be provided by torque source16.

Because compliant coupler 30 constitutes a torsion spring, a single partmay be used to absorb or cease the transmission of torque in response toan applied counter torque that results from sheet 12 encountering anobstruction. Because compliant coupler constitutes a torsion spring,torsion spring 18 may be replaced with a torsion spring having adifferent spring constant to adjust the predetermined amount of load orcounter torque that will trigger the cessation of the transmission oftorque (i.e., the level of torque at which the torsion spring will beginto twist). In addition, because complaint coupler 30 constitutes atorsion spring, compliant coupler 30 occupies relatively little space.In other embodiments, compliant coupler 30 may constitute otherstructures configured to reduce or cease the transmission of torque fromtorque source 16 to media drive member 14 in response to a predeterminedlevel of counter torque occurring as a result of sheet 12 encounteringan obstruction downstream.

FIG. 2 schematically illustrates media interaction system 50 whichincludes media feed system 110 a particular embodiment of media feedsystem 10 shown in FIG. 1. In addition to media feed system 110, mediainteraction system 50 generally includes media supply 52, mediatransport 54, torque source 56, sensor 58, media interaction device 60and controller 62. Media supply 52 constitutes one or more trays, bedsor other structures configured to support two side-by-side sheets 66Aand 66B of media or two side-by-side stacks of sheets 66A and 66Bproximate to media feed system 110 for simultaneous or near simultaneousfeeding or movement in parallel towards media transport 54 or towardsmedia interaction device 60 for simultaneous or near simultaneousinteraction by media interaction device 60. In the particular embodimentillustrated, supply 52 constitutes a single tray configured to supporttwo side-by-side stacks of sheets of media, such as photo paper. Inother embodiments; multiple side-by-side trays may alternatively beused. Although supply 52 is illustrated as supplying two side-by-sidesheets or stacks of sheets 66A, 66B of media, in other embodiments inwhich system 50 is configured to interact with more than two sheets at atime, supply 52 may also be configured to supply more than twoside-by-side sheets or stacks of sheets.

Media feed system 110 is similar to media feed system 10 except thatmedia feed system 110 is configured to feed or move two side-by-sidesheets 66A and 66B to a subsequent destination, such as media transport54, while ceasing the transmission of torque to one or both of suchsheets when such sheets encounter an obstruction. Media transport system110 includes media drive members 114A, 114B (collectively referred to asmedia drive members 114), torque source 116, and media drive trains 118Aand 118B (collectively referred to as drive trains 118). Media drivemembers 114 constitute one or more structures configured to frictionallyengage and drive a sheet of media. In the particular exampleillustrated, drive members 114A and 114B extend side-by-side one anotherto simultaneously engage sheets 66A and 66B, respectively. In theparticular example illustrated, members 114A and 114B constitute rollersextending along a common axis opposite sheets 66A and 66B, respectively.In other embodiments, members 14A and 114B may constitute other membersconfigured to frictionally engage and drive sheets of media, such as oneor more belts. In lieu of extending along a common axis, drive members114A and 114B may alternatively be staggered with respect to oneanother.

Torque source 116 constitutes one or more devices configured to supplytorque to drive members 114A and 114B via drive trains 118A and 118B,respectively. In the particular embodiment illustrated, torque source116 constitutes a single torque source operably coupled to both drivetrains 118A and 118B and operably coupled to both drive members 114A and114B. In the particular embodiment illustrated, torque source 116supplies the same level of torque to both drive trains 118A and 118B andboth drive rollers 114A and 114B. In the particular embodimentillustrated, torque source 116 constitutes an electric motor. In otherembodiments, torque source 116 may constitute other torque supplysystems.

Drive trains 118 each constitute a series of components operably coupledto one another between torque source 116 and associated drive member 114so as to serve as a transmission for transmitting torque from torquesource 116 to an associated drive member 114. In the particularembodiment illustrated, drive trains 118A and 118B-are substantiallyidentical to one another except that drive train 118 is operably coupledto drive member 114A and drive train 118B is operably coupled to drivemember 114B. Each of drive trains 118 includes a first torquetransmitting component 120, a second consecutive torque transmittingcomponent 122 and compliant coupler 130. Drive train components 122constitute members configured to transmit torque to their associateddrive members 114 which are connected to one another by compliantcoupler 130. Component 120 is operably coupled proximate to torquesource 116. Component 122 is operably coupled proximate to theassociated drive member 114.

In one embodiment, components 120 and 122 may constitute gears. In otherembodiments, components 120 and 122 may comprise other components of atransmission such as pulleys or sprockets or other similar mechanisms.In one embodiments, components 120 and 122 may be directly connected totorque source 116 and the associated drive member 114, respectively. Inanother embodiment, one or both of components 120 and 122 may beindirectly operably coupled to torque source 116 and the associateddrive member 114 by intermediate drive train components. In addition totransmitting torque, components 120 and 122 may additionally serve tochange or adjust the torque and speed from torque source 116.

Compliant coupler 130 compliantly couples or connects components 120 and122. Compliant coupler 130 is configured to transmit torque fromcomponent 120 to component 122 so as to transmit torque to drive member114. Coupler 130 is also configured to reduce or cease the transmissionof torque in response to receiving a counter force or counter torquesuch as when the sheet of media being driven by the respective drivemember 114 encounters an obstruction. In the particular exampleillustrated, in response to receiving a counter torque or force above apredetermined level, coupler 130 absorbs or stores torque that iscontinued to be supplied by torque source 116. In one embodiment,compliant coupler may constitute a torsion spring, wherein the torsionspring is twisted so as to reduce or cease or reduce transmission oftorque to component 122 and to the associated drive member 114 inresponse to the sheet being driven by drive member 114 encountering anobstruction. In other embodiments, compliant coupler 130 may constituteother springs.

Media transport 54 constitutes one or more devices configured to furthertransport or move sheets 66A and 66B provided by media feed system 110towards media interaction device 60. In one embodiment, media transport54 may include one or more rollers. In yet another embodiment, mediatransport 54 may constitute one or more belts.

Torque source 56 constitutes one or more devices configured to supplytorque to media transport 54 to drive media transport 54. In oneembodiment, torque source 56 may constitute an electric motor. In otherembodiments, torque source 56 may constitute other sources of torqueoperably coupled to media transport 54. In still other embodiments, asingle torque source may be used and operably coupled to media transport54 and drive trains 118 by clutching mechanisms and the like.

Sensor 58 constitutes one or more sensing devices in communication withcontroller 62 that are configured to sense or detect the positioning ofsheets 66A and 66B relative to media transport 54. In the particularexample illustrated, sensor 58 determines when leading edges of both ofsheets 66A and 66B are positioned in alignment with one anotherproximate to media transport 54. In other embodiments, sensor 58 mayalternatively be configured to sense when sheets 66A and 66B are out ofalignment or have not yet reached media transport 54. In one embodiment,sensor 58 may constitute optical sensors. In other embodiments, sensor58 may constitute one or more flags configured to be physicallycontacted by sheets 66A and 66B. In yet other embodiments, sensor 58 maybe omitted as will be described hereafter.

Media interaction device 60 constitutes a device configured to receivesheets 66A and 66B in a simultaneous or near simultaneous manner and tointeract with both sheets 66A and 66B. In one embodiment, mediainteraction device 60 is configured to print or otherwise form an image(text, graphics and the like) upon both sheets 66A and 66B. For example,in one embodiment, media interaction device 60 may constitute one ormore inkjet printheads configured to deposit ink upon sheets 66A and66B. In yet other embodiments, media interaction device 60 may beconfigured to form other functions such as scanning information fromsheets 66A and 66B, collating, organizing or folding sheets 66A and 66Bor other interactions.

Controller 62 constitutes a processing unit configured to analyzeinformation received from sensor 58 and to generate control signalsdirecting the operation of at least torque source 116, torque source 56and media interaction device 60. For purposes of this disclosure, theterm “processing unit” shall mean a presently developed or futuredeveloped processing unit that executes sequences of instructionscontained in a memory. Execution of the sequences of instructions causesthe processing unit to perform steps such as generating control signals.The instructions may be loaded in a random access memory (RAM) forexecution by the processing unit from a read only memory (ROM), a massstorage device, or some other persistent storage. In other embodiments,hard wired circuitry may be used in place of or in combination withsoftware instructions to implement the functions described. Controller62 is not limited to any specific combination of hardware circuitry andsoftware, nor to any particular source for the instructions executed bythe processing unit.

In operation, in response to receiving instructions that sheets 66A and66B are to be interacted upon by media interaction device 60, such as byprinting upon sheets 66A and 66B, controller 62 generates controlsignals causing torque source 116 to supply torque to each of rollers114A and 114B via drive trains 118A and 118B, respectively. In oneembodiment, controller 62 further generates control signals directingtorque source 56 to drive media transport 54 in a first direction suchthat media transport 54 opposes or obstructs movement of the leadingedges of sheets 66A and 66B beyond media transport 54. In otherembodiments, media transport 54 may be used to obstruct sheets 66A and66B without being rotatably driven or other structures may be used totemporarily block or obstruct the leading edges of sheets 66A and 66B.

As a result of receiving torque from torque source 116 through drivetrains 118, drive members 114 roll against a top surface of sheets 66Aand 66B to move sheets 66A and 66B towards media transport 54. Shouldone of sheets 66A, 66B arrive at media transport 54 before the other,the first arriving sheet is obstructed by media transport 54 such that acounter torque or force is applied to drive train component 122. As aresult, the end of compliant coupler 130 connected to member 122 doesnot rotate while the opposite end of complaint coupler 130 connected todrive train component 120 continues to rotate, twisting compliantcoupler 130. Even though torque is continued to be supplied from torquesource 116, such torque is not transmitted to the associated drivemember 114. As a result, continued movement of the first arriving sheet66A, 66B is stalled or paused with minimal crumpling or damaging of suchsheet until the other later sheet 66A, 66B arrives at media transport54.

Upon both sheets 66A and 66B being moved proximate to media transport54, sensor 58 transmits a signal to controller 62. As a result,controller 62 generates control signals directing torque source 56 todrive media transport 54 in a direction such that the now aligned oradjacent leading edges 66A and 66B are further transported towards mediainteraction device 60 for being interacted by media interaction device60.

Although system 50 is illustrated as including sensor 58, in otherembodiments, system 50 may omit sensor 58, wherein controller 62 isconfigured to generate control signals directing torque source 56 todrive media transport 54 in a direction such that media transport 54blocks or obstructs further movement of sheets 66A, 66B for a period oftime equal to or greater than a predetermined maximum time period thatone of sheets 66A, 66B may be delayed with respect to the other ofsheets 66A, 66B.

FIG. 3 schematically illustrates media interaction system 250, anotherembodiment of system 50 shown in FIG. 2. System 250 includes mediasupply 52, media feed system 110, media transport 54, sensor 55 andinteraction device 60. In the particular example illustrated in FIG. 3,media transport 54 includes turn roller 252, idler roller 254, feedroller 256 and idler roller 258. Turn roller 252 cooperates with idlerroller 254 to frictionally engage sheets 66A and 66B (shown in FIG. 2)from media supply 52 and to transport such sheets in an arc towards feedroller 256 and idler roller 258. Feed roller 256 cooperates with idlerroller 258 to frictionally engage sheets 66A and 66B therebetween todrive sheets 66A, 66B towards interaction device 60. The positioning ofsheets 66A, 66B is detected by sensor 55 which is illustrated as a flagwhich is pivoted or triggered in response to being physically engaged bysheets 66A and 66B as such sheets are being driven by turn roller tofeed roller 256. Feed roller 256 and idler roller 258 drive sheets 66Aand 66B across a platen 260 opposite interaction device 60.

In the particular example illustrated, interaction device 60 depositsink upon sheets 66A and 66B. Although not illustrated, system 250additionally includes one or more torque sources 56 (shown in FIG. 2)configured to rotatably drive turn roller 252 and feed roller 256,sensor 58 (shown in FIG. 2) and controller 62 (shown in FIG. 2) incommunication with torque source 56, as well as torque source 116 (shownin FIG. 2) of media feed system 110. In the particular exampleillustrated, controller 62 is further in communication with sensor 55 soas to receive signals from sensor 55 indicating the positioning ofsheets 66A, 66B.

FIG. 3 schematically illustrates various travel distances for sheets 66Aand 66B (shown in FIG. 2) from supply 52 to turn roller 252 of mediatransport 54. FIG. 3 provides a comparison of different travel distancesfor a single sheet 66 resting upon supply 52 or a sheet 66 resting upona full stack 266 of such sheets upon supply 52. As shown by FIG. 3, asingle sheet 66 travels a distance D1 much greater than the distance D2traveled by a sheet 66 taken from a full stack. In particular scenarios,sheets 66A and 66B may be taken from differently sized stacks upon media52. Due to the different travel distances, this may result in one ofsheets 66A, 66B (show in FIG. 2) arriving at media transport 54 beforethe other. However, as noted above, the first sheet 66 arriving at mediatransport 54 will be obstructed such that compliant coupler 130 (shownin FIG. 2) reduce or ceases the transmission of torque to the particulardrive member 114A, 114B that is driving the first arriving sheet. Suchtransmission of torque will be paused until the later arriving sheet 66,such as a sheet taken from a smaller stack, arrives, at which point,media transport 54 will continue to drive both sheets 66A, 66B (shown inFIG. 2) in a simultaneous or near simultaneous fashion towards feedroller 256 and interaction device 60.

FIG. 4 illustrates media feed system 310, another embodiment of mediafeed system 10 shown in FIG. 1. Media feed system 310 is configured foruse in a media interaction system such as media interaction system 50.Media feed system 310 is configured to feed or move a sheet of mediafrom a supply (not shown) to a subsequent destination such as mediatransport 54 (shown in FIG. 2). Media feed system 310 includes torquesource 116 (described with respect to FIG. 2), media drive member 314,drive train 318 and support 319. Torque source 116 is described abovewith respect to FIG. 2. Torque source 116 supplies torque to drivemember 314 through drive train 318.

Drive member 314 is configured to rotate about axis 324 in response toreceiving torque from drive train 318. Drive member 314 is configured tofrictionally engage a surface of a sheet of media to drive the media. Inthe particular example illustrated, drive member 314 constitutes aroller or tire configured to pick or separate a sheet of media from asupport or underlying stack of remaining sheets.

Drive train 318 serves as a transmission for transmitting torque fromtorque source 116 to media drive member 314. Drive train 318 generallyincludes drive shaft 326, gears 328, 330, 332, 334, 336, 338, 340 andcompliant coupler 342. Drive shaft 326 constitutes an elongate shaftcoupled to support 319 and operably coupled to torque source 116 so asto be rotatably driven about axis 346. Drive shaft 326 carries gear 328so as to rotatably drive gear 328. Although drive shaft 326 isillustrated as supplying torque to a single series of gears 328-340 anda single pick tire 314, drive shaft 326 may also supply torque toadditional series of gears 328-340 and additional drive members 314spaced along shaft 326.

Gears 328-340 transmit torque from drive shaft 326 to media drive member314. Gear 328 is fixed to drive shaft 326. Gear 330 is in meshingengagement with gears 328 and 332. Gear 332 is in meshing engagementwith gear 330 and gear 342. Gear 342 is connected to gear 336 bycompliant coupler 342. Gear 336 is in meshing engagement with gear 338.Gear 338 is in meshing engagement with gear 340 which is fixed to mediadrive member 314. Gear 336 is coaxial with gear 334 and is in meshingengagement with gear 338.

Compliant coupler 342 transmits torque between gears 334 and 336 suchthat torque is transmitted from torque source 116 to media drive member314. Compliant coupler 342 is further configured to reduce or cease thetransmission of torque between gears 334 and 336 upon experiencing acounter torque or counter force which may occur as a result of the sheetof media being driven by media drive member 314 encountering anobstruction. In the particular example illustrated, compliant coupler342 constitutes a torsion spring having a first end 350 (shown in FIG.5) connected to gear 334 and a second end 352 connected to gear 336. Asa result, upon experiencing a counter torque, complaint coupler 340twists, allowing gear 334 to continue to rotate while gear 336 isstationary or rotates at a lesser rate. In other embodiments, compliantcoupler 342 may comprise other structures configured to reduce or ceasetransmission of torque between gears 334 and 336.

Support 319 constitutes one or more structures configured to rotatablysupport gears 330, 332, 334, 336, 338 and 340, compliant coupler 342 andmedia drive member 314. Support 319 connects gears 330-340, coupler 342and media drive member 314 as a single assembled unit to be removed,repaired or replaced. As a result, additional such units may be operablyconnected to drive shaft 326 along axis 346 to facilitate simultaneousor near simultaneous feeding of two or more sheets in a mediainteraction system.

FIG. 5 illustrates gears 334, 336 and compliant coupler 342 in greaterdetail. As shown by FIG. 5, gear 334 includes main body, hub 362 andbore 363. Main body 360 includes teeth 364 and coupler detents 366.Teeth 364 mesh correspondingly to teeth of gear 332 (shown in FIG. 4).

Coupler detents 366 constitute depressions or openings formed withinbody 360 that are configured to receive end 350 of coupler 342. In theparticular embodiment illustrated, body 360 includes a multitude ofspaced detents 366. As a result, end 350 of coupler 342 may be connectedto body 360 of gear 334 at one of a multitude of different locationsabout axis 368 of gear 334 to facilitate adjustment of a preload appliedto coupler 342.

In the particular example illustrated, each detent 366 is a radiallyextending elongate slot configured to receive end 350 of coupler 342. Asa result, detents 366 permit end 350 to move in a radially inwarddirection as end 350 complies or twists relative to end 352 in responseto rotation of gear 334. Because detents 366 constitute slots permittingsuch radial inward movement of end 350, less strain is imposed uponcoupler 342. In other embodiments, body 360 may alternatively include asingle detent 366 or a fewer or greater number of such detents 366. Instill other embodiments, in lieu of constituting slots, detents 366 maycomprise other bores or openings.

Hub 362 axially projects from body 360 and is configured to mate withgear 336 so as to axially capture coupler 342 between gears 334 and 336.Hub 362 includes a raised surface 370, a recessed surface 372 and a pairof shoulders 374 extending therebetween to form an opening or notch 375.Raised surface 370 abuts a portion of gear 336 to axially position gear334 with gear 336. Notch 375 cooperates with gear 336 to limit relativerotation of gear 334 relative to gear 336 as will be described ingreater detail hereafter.

Gear 336 transmits torque received via coupler 342 to gear 338 (shown inFIG. 4). Gear 336 generally includes body 380 and hub 382. Body 380includes teeth 384 and coupler detent 386. Teeth 384 circumferentiallyextend about body 380 and are configured to intermesh with correspondingteeth of gear 338 (shown in FIG. 4).

Coupler detent 386 constitutes a depression, bore or other openingextending at least partially into body 380 and configured to receive end352 of coupler 342 to connect end 352 to gear 336. Like coupler detents366, coupler detent 386 constitutes an elongate radially extending slotconfigured to permit radially inward movement of end 352 as end 350 ofcoupler 342 is rotated relative to end 352 to twist coupler 342 whencoupler 342 is ceasing or reducing transmission of the torque betweengears 334 and 336. Because detent 386 permits radial inward movement ofend 352 during twisting of coupler 342, detent 386 lessens stress uponend 352 and gear 336. In other embodiments, detent 386 may alternativelyconstitute a cylindrical bore or other openings. Although gear 336 isillustrated as including a single detent 386, in other embodiments, gear336 may include multiple detents within body 380.

Hub 382 facilitates connection of gear 336 to gear 334 and retention ofcoupler 342 between gears 334 and 336. Hub 382 generally includesrecessed surfaces 390, projection 392 and prongs 394. Recessed surfaces390 face in an axial direction and abut raised surface 370 of gear 364along a junction to axially space body 380 of gear 336 from body 360 ofgear 334 when gears 334 and 336 are connected to permit capturing ofcoupler 342 between gears 334 and 336. Gears 334 and 336 move relativeto one another when torque is not being fully transmitted between gears334 and 336 by coupler 342 along this junction. In the particularembodiment illustrated, the junction formed between gears 334 and 336extends beneath a central portion of the torsion spring of coupler 342.In other words, torsion spring 342 overlies the junction. As a result,the assembly of gears 334, 336 and coupler 342 is facilitated and alikelihood of coupler 342 becoming caught at the juncture of gears 334and 336 is reduced.

Projection 392 axially projects beyond surfaces 390 and is configured toreceive between shoulders 374 and against recessed surface 372 of hub362 of gear 334. Projection 392 abuts one of shoulders 370 to limitrotation of gear 334 relative to gear 336 to an angle of less than 360degrees when torque is not being fully transmitted between gears 334 and336 by coupler 342. In one particular embodiment, shoulders 370 arecircumferentially spaced from one another and projection 392 isconfigured such that gear 334 is permitted to rotate a maximum of 83degrees about axis 368 relative to gear 336 which will produce 15.3 mmcompliant distance at pick tire 314. As a result, a time during whichtorque is not transmitted between gears 334 and 336 and during whichcompliant coupler 342 is twisted to absorb such torque is limited toprevent damage to coupler 342. In other embodiments, the notch or cutoutprovided between shoulders 374 and the size or dimensions of projections392 may be altered such that the rotation of gear 334 relative to gear336 is limited by different angular extents. In still other embodiments,the notch 375 provided by recessed surfaces 372 and shoulders 374 aswell as projection 392 may be omitted.

Prongs 394 axially project to recessed surfaces 390 and are configuredto extend through bore 363 of gear 334 so as to resiliently engage anopposite side of gear 334 to releasably connect gear 336 to gear 334.Prongs 394 resiliently urge recessed surfaces 390 against raised surface370 to axially retain gears 334 and 336 to one another so as to capturecoupler 342 axially therebetween with ends 350 and 352 received withindetents 366 and 386, respectively. Prongs 394 facilitate efficientassembly of gears 334, 336 and coupler 342 to reduce manufacturingcomplexity and cost.

In other embodiments, gears 334 and 336 may be permanently or releasablyconnected to one another by other methods. For example, in otherembodiments, gears 334 and 336 may be connected to one another by one ormore fasteners extending therebetween. In still other embodiments, gears334 and 336 may be connected to one another by adhesives, welding orother resilient inter-engagement structures, such as prongs 394.

Overall, gears 334, 336 and coupler 342 enable relatively easyincorporation of compliant coupler 342 into drive train 318 (shown inFIG. 4) with a reduced number of parts and less complex assembly. Gears334 and 336 further enable a preload of coupler 342 to be selectivelyadjusted for varying conditions. At the same time, the notch 375provided between shoulders 370 receiver projection 392 permit control ofthe extent to which gear 334 rotates relative to gear 336 when thetransmission of torque between gears 334 and 336 is reduced or ceased bycoupler 342.

In other embodiments, gears 334 and 336 may be switched such that gear336 is in meshing engagement with gear 318 and gear 334 is in meshingengagement with gear 338. In still other embodiments, ends 350 and 352of compliant coupler 342 may be connected to gears 334 and 336 in otherfashions other then detents 366 and 386. In still other embodiments,projection 392 and the cutout provided between shoulders 370 may beomitted.

Although the present disclosure has been described with reference toexample embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the claimed subject matter. For example, although differentexample embodiments may have been described as including one or morefeatures providing one or more benefits, it is contemplated that thedescribed features may be interchanged with one another or alternativelybe combined with one another in the described example embodiments or inother alternative embodiments. Because the technology of the presentdisclosure is relatively complex, not all changes in the technology areforeseeable. The present disclosure described with reference to theexample embodiments and set forth in the following claims is manifestlyintended to be as broad as possible. For example, unless specificallyotherwise noted, the claims reciting a single particular element alsoencompass a plurality of such particular elements.

1. An apparatus comprising: at least one first torque source; a firstsurface configured to be rolled against a first medium; and a firsttorsion spring operably coupled between the at least one first torquesource and the first surface.
 2. The apparatus of claim 1 furthercomprising a drive train between the torque source and the firstsurface, wherein the first torsion spring is operably coupled betweenconsecutive members of the drive train.
 3. The apparatus of claim 1further comprising: a first member operably coupled to the surface; anda second member operably coupled to the torque source, wherein thetorsion spring has a first portion connected to the first member and asecond portion connected to the second member.
 4. The apparatus of claim3, wherein the first member includes a first radial slot receiving thefirst portion of the torsion spring and wherein the second memberincludes a second radial slot receiving the second portion of the secondmember.
 5. The apparatus of claim 3, wherein the first member and thesecond member comprise gears.
 6. The apparatus of claim 3, wherein thefirst member and the second member are configured to rotate a maximumangle of less than 360 degrees relative to one another.
 7. The apparatusof claim 3, wherein the torsion spring and one of the first member andthe second member are configured to be selectively coupled to oneanother at one of a plurality of locations to adjust a preload of thefirst torsion spring.
 8. The apparatus of claim 3, wherein the firstmember and the second member rotate about an axis and wherein the firsttorsion spring is axially between the first member and the secondmember.
 9. The apparatus of claim 8, wherein the first member and thesecond member are axially connected to one another while being rotatableto one another about the axis.
 10. The apparatus of claim 8, wherein thefirst member and the second member are connected along a junctureoverlapped by the first torsion spring.
 11. The apparatus of claim 1further comprising: a second surface configured to be rolled against asecond medium; and a second torsion spring operably coupled between theat least one torque source and the second surface.
 12. The apparatus ofclaim 11, wherein the at least one torsion source comprises a singletorsion source operably coupled to both the first surface and the secondsurface.
 13. The apparatus of claim 11, wherein the first surface andthe second surface are configured to be simultaneously rolled againstthe first medium and the second medium while the first medium and thesecond medium extend side-by-side one another.
 14. The apparatus ofclaim 13 further comprising at least one tray configured to support thefirst medium adjacent the first surface and the second medium adjacentthe second surface.
 15. The apparatus of claim 11 further comprising amedia interaction device configured to interact with the first mediumand the second medium while the first medium is aligned with the secondmedium.
 16. The apparatus of claim 11 further comprising a mediatransport configured to move the first medium and the second medium in afirst direction simultaneously.
 17. The apparatus of claim 16 furthercomprising: a second torque source coupled to the media transport; and acontroller configured to generate control signals causing the mediatransport to oppose movement of at least one of the first medium and sthe second medium in the first direction until both the first medium andthe second medium are adjacent the media transport.
 18. The apparatus ofclaim 17 further comprising a sensor configured to sense the positioningof both of the first medium and the second medium adjacent the mediatransport.
 19. The apparatus of claim 17, wherein the controller isconfigured to generate the control signals such that the media transportopposes movement of the first medium for a predetermined maximum timethat the second surface may take to move the second medium to the mediatransport.
 20. The apparatus of claim 17 further comprising a mediainteraction device configured to interact with the first medium.
 21. Amedia feed device comprising: at least one torque source; a firstsurface configured to be rolled against a medium; and a drive trainbetween the at least one torque source and the first surface, the drivetrain configured to reduce the transmission of torque betweenconsecutive members of the drive train in response to a predeterminedamount of torque applied to the first surface.
 22. The device of claim21 further comprising: a second surface configured to be rolled againsta second medium; and a second drive train operably coupled between thetorque source and the second surface, the second drive train beingconfigured to reduce or cease transmission of torque between consecutivemembers of the drive train in response to a predetermined amount ofcounter torque applied to the second surface.
 23. The device of claim 22further comprising a drive shaft operably coupled to the at least onetorque source, wherein the first drive train is configured as a firstunitary assembly, wherein the second drive train is configured as asecond unitary assembly and wherein the first assembly and the secondassembly are removably connected to the drive shaft and receive torquefrom the drive shaft.
 24. The device of claim 21, wherein the firstdrive train includes a torsion spring.
 25. The device of claim 21,wherein the first drive train comprises: a first gear; a second gear;and a torsion spring having a first end connected to the first gear anda second end connected to the second gear.
 26. A media feed systemcomprising: a torque source; a surface configured to be rolled against amedium; and a drive train between the torque source and the surface, thedrive train including means for reducing transmission of torque betweenconsecutive members of the drive train in response to a predeterminedamount of counter torque applied to the surface.
 27. A media feed unitcomprising: a support; a roller rotatably coupled to the support; gearsrotatably coupled to the support and configured to transmit torque tothe roller; and a torsion spring having a first end connected to one ofthe gears and a second end connected to another of the gears.
 28. Amethod comprising: transmitting torque from a torque source with a drivetrain to a drive member contacting a medium; and ceasing transmission oftorque between consecutive members of the drive train in response to apredetermined amount of counter torque applied to the drive member. 29.The method of claim 28, wherein the ceasing includes rotating a firstdrive train member relative to a second drive train member.
 30. Themethod of claim 29, wherein the ceasing further includes twisting atorsion spring connected to the first drive train member and the seconddrive train member.